[Ruiji takeout] day05 package management business development

Catalog

1. New package
2. Paging query of package information
3. Delete package

New package _ Demand analysis & Data model

Demand analysis

• A set meal is a collection of dishes
• Package information can be managed in the background system , Add a new package through the new package function
• When adding a package, you need Select the Package classification and Dishes included , And need Upload the picture corresponding to the package
• On the mobile end Show the corresponding packages according to the package classification

Data model

• New package , In fact, that is Insert the package information entered on the new page into setmeal surface , We also need to setmeal_dish surface Insert set meal and dish Association data
• So when adding a package , It involves two tables :

1. setmeal---- Package list
2. setmeal_dish---- Relationship table of package dishes

New package _ Code development _ preparation & Sort out the interaction process

Code development - preparation

Before developing business functions , First, create the basic structure of classes and interfaces that need to be used :

• Entity class SetmealDish( Import directly from the course materials ,Setmeal The entity has been imported in the previous course )
• DTO SetmealDto ( Import directly from the course materials )
• Mapper Interface SetmealDishMapper
• Business layer interface SetmealDishService
• Business layer implementation classes SetmealDishservicelmpl
• Control layer SetmealController

Code development - Sort out the interaction process

Before developing code , You need to sort out the interaction process between the front-end page and the server when adding a package :

1. page (backend/page/combo/add.html) send out ajax request , Request server Get the package classification data and display it in the drop-down box （ Completed ）
2. Page sending ajax request , Request server , Get dish classification data And show it in the add dishes window
3. Page sending ajax request , Request server , Query the corresponding dish data according to the dish classification And show it in the add dishes window
4. The page sends a request for pictures Upload , Request the server to save the picture to the server （ Completed ）
5. The page sends a request for pictures download , Echo the uploaded picture （ Completed ）
6. Click the save button , send out ajax request , The data related to the package is displayed in json Submit to the server in the form of

Develop new package functions , In fact, it is to write code on the server side to process the information sent by the front-end page 6 One request is enough

New package _ Code development _ Query dishes according to classification

Front end analysis

Start project , Enter package management , Click new package , You will find that the request sent by the page is not received by the server

Explosion system interface is abnormal , The server does not define the method of querying dishes

Related codes

stay DishController Class , add to list Method
Be careful ： Additional query criteria need to be added , Query only status by 1 The data of , Indicates that the dish is in the starting status , Can be added to the package , For user selection

@GetMapping("/list")
    public R<List<Dish>> list(Dish dish){

        // Construct query conditions 
        LambdaQueryWrapper<Dish> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(dish.getCategoryId() != null, Dish::getCategoryId, dish.getCategoryId());
        // Adding conditions , The query status is 1（1 For initial sale ,0 To stop selling ） The dishes 
        queryWrapper.eq(Dish::getStatus,1);

        List<Dish> list = dishService.list(queryWrapper);
        // Add sorting criteria 
        return R.success(list);
    }

New package _ Code development _ The server receives the data submitted by the page

Front end analysis

Start project , Go to the add package page , input data , Click save

View the request sent by the front page , Request mode

Related codes （ The beta ）

stay SetmealController Class save Method

Implementation class SetmealServicelmpl, Implement the method of interface addition , And add code logic to the method

• Save the basic information of the package
• Save the related information of packages and dishes

@Override
    @Transactional
    public void saveWithDish(SetmealDto setmealDto) {
        // Save the basic information of the package , operation setmeal, perform insert operation 
        save(setmealDto);

        List<SetmealDish> setmealDishes = setmealDto.getSetmealDishes();

        setmealDishes = setmealDishes.stream().map((item) -> {
            item.setSetmealId(setmealDto.getId());
            return item;
        }).collect(Collectors.toList());

        // Save the related information of packages and dishes 
        setmealDishService.saveBatch(setmealDishes);
    }

stay SetmealController The control layer save In the method , call saveWithDish Method , Save data to database

 @PostMapping
    public R<String> save(@RequestBody SetmealDto setmealDto){
        log.info(" Data transmission object setmealDto:{}",setmealDto.toString());
        setmealService.saveWithDish(setmealDto);
        return R.success(" Successfully added package ");
    }

Paging query of package information _ Demand analysis & Sort out the interaction process

Demand analysis

• When there are a lot of package data in the system , If you show it all in one page, it will look messy , Not easy to view
• In general, the list data will be displayed in the way of paging

Sort out the interaction process

Before developing code , You need to sort out the interaction process between the front-end page and the server during package paging query :

• page (backend/page/combo/list.html) send out ajax request , Paging query parameters (page、pageSize、name) Submit to the server , Get paging data
• Page send request , Request the server to download pictures , For page image display

Develop the paging query function of package information , In fact, it is to write code on the server side to process the information sent by the front-end page 2 One request is enough

Paging query of package information _ Code development & A functional test

Code development

SetmealController Class , add to list Method

@GetMapping("/page")
    public R<Page> list(int page,int pageSize,String name){
        // Page builder object 
        Page<Setmeal> pageInfo = new Page<>(page, pageSize);
        Page<SetmealDto> dtoPage = new Page<>();

        // Construct query criteria object 
        LambdaQueryWrapper<Setmeal> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(name != null, Setmeal::getName, name);

        // Operating the database 
        setmealService.page(pageInfo,queryWrapper);

        // Object Copy 
        BeanUtils.copyProperties(pageInfo,dtoPage,"records");

        List<Setmeal> records = pageInfo.getRecords();

        List<SetmealDto> list = records.stream().map((item) -> {
            SetmealDto setmealDto = new SetmealDto();
            BeanUtils.copyProperties(item, setmealDto);
            // obtain categoryId
            Long categoryId = item.getCategoryId();
            Category category = categoryService.getById(categoryId);
            if (category != null) {
                String categoryName = category.getName();
                setmealDto.setCategoryName(categoryName);
            }
            return setmealDto;
        }).collect(Collectors.toList());

        dtoPage.setRecords(list);

        return R.success(dtoPage);
    }

Be careful
In the package management interface , The package category field displays categoryId Corresponding Chinese , But what you find in the database is categoryId, So we need to use categoryId Query to categoryName, And assign it to the data transmission object SetmealDto

Delete package _ Demand analysis & Sort out the interaction process

Demand analysis

• Click the delete button on the package management list page , You can delete the corresponding package information
• You can also select multiple packages through the check box , Click the batch delete button to delete multiple packages at one time
• Be careful , Packages in sale status cannot be deleted , Need to stop selling , Then delete .

Sort out the interaction process
Before developing code , You need to sort out the interaction process between the front-end page and the server when deleting the package :

• When deleting a single package , Page sending ajax request , According to the package id Delete the corresponding package
• When deleting multiple packages , Page sending ajax request , According to multiple packages submitted id Delete the corresponding package development delete package function

In fact, it is to write code on the server side to process the information sent by the front-end page 2 One request is enough

• By observing the request information of deleting single packages and batch packages, we can find , The address and request method of the two requests are the same Of
• The difference is transmitted id Number , Therefore, a method can be provided on the server side to handle .

Delete package _ Code development & A functional test

Code development （ test ）

stay SetmealController Add delete Method

 @DeleteMapping
    public R<String> delete(@RequestParam List<Long> ids){
        log.info("ids by ：",ids);

        return null;
    }

Code development perfect version

1. stay SetmealService Add to interface removeWithDish Method

2. stay SetmealServicelmpl Implement the methods added in the corresponding interface in the implementation class

@Override
    @Transactional
    public void removeWithDish(List<Long> ids) {
        //select count(*) from setmeal where ids in(1,2,3) and status = 1
        // Query package status , Determine if you can delete 
        LambdaQueryWrapper<Setmeal> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.in(Setmeal::getId,ids);
        queryWrapper.eq(Setmeal::getStatus,1);

        int count = super.count(queryWrapper);

        if (count > 0){
            // If you can't delete , Throw a business exception 
            throw new CustomException(" The package is on sale , Can't delete ");
        }

        // If you can delete , First delete the data in the package table 
        super.removeByIds(ids);

        // Delete data in relation table 
        //delete from setmeal_dish where setmeal_id in(1,2,3)
        LambdaQueryWrapper<SetmealDish> dishLambdaQueryWrapper = new LambdaQueryWrapper<>();
        dishLambdaQueryWrapper.in(SetmealDish::getSetmealId,ids);

        setmealDishService.remove(dishLambdaQueryWrapper);


    }

stay SetmealController Improve the code — call removeWithDish Method , Successfully delete the package data

@DeleteMapping
    public R<String> delete(@RequestParam List<Long> ids){
        log.info("ids by ：",ids);
        setmealService.removeWithDish(ids);
        return R.success(" Package data deleted successfully ");

    }